1. Field of the Invention
The present invention relates to a hitch for pulling powered lawn mowers behind a lawn tractor.
2. Description of the Prior Art
The prior art has long recognized the desirability of ganging together a plurality of pushed mower units, and drawing the same behind a tractor or the like. A lawn is more quickly mowed by operating several mowers simultaneously. Also, it is much easier to ride on a powered tractor than to push one or more mowers without powered assistance.
Small tractors have been developed for this purpose, as well as to draw small loads, compared to commercial farming. It would be relatively easy to connect a group of mower units which were originally intended to be individually operated in order to achieve the practical grouping described above. Accordingly, hitches for mounting to a tractor and to two or more mower units have been proposed, and several examples will be discussed.
Tow hitches for pulling two powered push mowers behind a lawn tractor are seen in U.S. Pat. Nos. 1,582,947, issued to Hayden W. Wagner et al. on May 4, 1926; 3,514,126, issued to William H. Fuss on May 26, 1970; and 4,744,580, issued to Charles C. Ryan on May 17, 1988. In the first example, a draw bar is pivotally mounted to the tractor, which in this example has an integral first power mower unit. The draw bar attaches to the frames of the two drawn mowers by, at each point of attachment, a special joint incorporating one vertical and one horizontal pivot pin. The combination of pivoting about two orthogonal axes provides universally pivotal adjustment, and will hereinafter be termed a universal joint.
The draw bar of the second example is solidly mounted to the tractor. A bracket is solidly mounted to each mower, and a link connects each bracket to the draw bar. The link loosely fits the draw bar and the respective brackets, resultant play thus accommodating maneuvering, turning, and uneven ground.
In the device of Ryan '580, the draw bar comprises a solid unitary member. Each mower is attached thereto by a short chain anchored to the draw bar at a bolt. Another similar arrangement is described in U.S. Pat. No. 3,608,284, issued to Leon P. Erdman on Sep. 28, 1971. The mowers of Erdman '284 are not self-contained, pushed, power mowers, but are specially designed to cooperate with the tow hitch.
A hitch seen in U.S. Pat. No. 3,757,500, issued to Marnie C. Averitt on Sep. 11, 1973, yokes two mowers abreast, behind a tractor. The mowers are adjustably spaced apart by telescoping members, but in other respects are solidly joined.
A ganged arrangement for drawing three push mowers behind a lawn tractor is disclosed in U.S. Pat. No. 4,815,259, issued to Wayne Scott on Mar. 28, 1989. A first hitch connects the tractor to a lead mower. Two additional mowers are connected to the lead mower by a second hitch. The first hitch is configured in a "T" shape, the stem of the T attaching to the lead mower, and the top of the T spanning and attaching to the front right and front left corners of the mower deck. The second hitch is configured generally in "U" form, the base of the U spanning and attaching to rear right and left corners of the mower deck, and the upright segments of the U connecting to the trailing mowers. The upright segments of the U terminate in tees, so as to attach to their respective mower units in the same manner as the lead mower is connected to the tractor.
U.S. Pat. No. 3,134,079, issued to Thomas J. Dunn on Jun. 2, 1964, discloses an apparatus incorporating three drawn mower units and a draft bar.
An asymmetric arrangement is seen in U.S. Pat. No. 3,832,834, issued to George E. Kovacs on Sep. 3, 1974. A draw bar attaches to two mowers, one located behind and to the side of the first. A partial frame holds the trailing mower in this orientation.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.